M4
The M4 carbine is a family of firearms tracing its lineage back to earlier carbine versions of the M16, all based on the original AR-15 designed by Eugene Stoner and made by ArmaLite. It is a shorter and lighter version of the M16A2 assault rifle, with 80% parts commonality. It is a gas-operated, air-cooled, magazine-fed, selective fire, shoulder-fired weapon with a telescoping stock. A shortened variant of the M16A2 rifle, the M4 has a 14.5 in (370 mm) barrel, allowing the individual soldier to better operate in close quarters. The M4 has selective fire options including semi-automatic and three-round burst (like the M16A2), while the M4A1 has the capability to fire fully automatic instead of three-round burst. The carbine is also capable of mounting an M203 grenade launcher, the M203A1 with a 9-inch barrel as opposed to the standard 12-inch barrel of the M203 used on the M16 series. The M4 carbine is slated to eventually replace the M16 rifle for most combat units in the United States Army.The winner of the Individual Carbine competition may replace the M4 carbine in U.S. Army service. Design The M4 and its variants fire 5.56x45mm NATO ammunition (and .223 Remington ammunition) and are gas-operated, air-cooled, magazine-fed, selective fire firearms with either a multi-position telescoping stock or a fixed A2 or LE tactical stock. Original M4 models had a flat-ended telescoping stock, but newer models are now equipped with a redesigned telescoping stock that is slightly larger with curvature at the end.[[|14]] The M4 is similar to much earlier compact M16 versions, such as the 1960s-era XM177 family. Some of those visual designs are obvious in both weapons, however most of the similarities are not very noticeable. As with many carbines, the M4 is handy and more convenient to carry than a full-length rifle. The price is slightly inferior ballistic performance compared to the full-size M16, with its nearly 6" (15 cm) longer barrel. This becomes most apparent at ranges of 300 yards and beyond. Statistically, however, most small-arms engagements occur within 100 yards. This means that the M4 is very much an adequate weapon for the majority of troops. The marginal sacrifice in terminal ballistics and range, in exchange for greatly improved handling characteristics, is usually thought to be a worthwhile compromise. While the M4's maneuverability makes it a candidate for non-infantry troops (vehicle crews, clerks and staff officers), it also makes it ideal for close quarters battle (CQB). The M4 was developed and produced for the United States government by Colt Firearms, which had an exclusive contract to produce the M4 family of weapons through 2009; however, a number of other manufacturers offer M4-like firearms. The M4, along with the M16A4, have mostly replaced the M16A2 in the Army and Marines. The U.S. Air Force, for example, has transitioned completely to the M4 for Security Forces squadrons, while other armed personnel retain the M16A2. The US Navy uses M4A1s for Special Operations and by vehicle crews. Some features of the M4 and M4A1 compared to a full-length M16-series rifle include: *Compact size perfect for indoor battles *Shortened barrel 14.5 in (370 mm) *Telescoping buttstock for use of medium range combat However, there have been some criticisms of the carbine, such as lower muzzle velocities and louder report due to the shorter barrel, additional stress on parts because of the shorter gas system, and a tendency to overheat faster than the M16A2. Attachments Like all the variants of the M16, the M4 and the M4A1 can be fitted with many accessories, such as night vision devices, suppressors, laser pointers, telescopic sights, bipods, either the M203 or M320 grenade launchers, the M26 MASS shotgun,forward hand grips and anything else compatible with a MIL-STD-1913 Picatinny rail. Other common accessories include the AN/PEQ-2, Advanced Combat Optical Gunsight (ACOG), and M68 CCO. EOTech holographic weapon sights are part of the SOPMOD II package. Visible and IR (infrared) lights of various manufacturers are also commonly attached using various mounting methods. As with all versions of the M16, the M4 accepts a blank-firing attachment (BFA) for training purposes. FeedRamps M4 feedramps are extended from the barrel extension into the upper receiver. This can help alleviate feeding problems which may occur as a result of the increased pressure of the shortened gas system of the M4. This problem is primarily seen in full-auto applications. While some feel they are unnecessary, their perceived or real utility to others has led to the increasing availability of this feature on civilian AR-15 products. left|thumb|300px|One M4 can make ones dream come true. Variants Except for the very first delivery order, all U.S. military-issue M4 and M4A1 carbines possess a flat-top NATO M1913-specification (Picatinny) rail on top of the receiver for attachment of optical sights and other aiming devices — Trijicon TA01 and TA31 Advanced Combat Optical Gunsights (ACOG), EOTech 550 series holographic sights, and Aimpoint M68 Close Combat Optic (M68 CCO) being the favorite choices — and a detachable rail-mounted carrying handle. Standards are the Colt Model 920 (M4) and 921 (M4A1). Variants of the carbine built by different manufacturers are also in service with many other foreign special forces units, such as the Australian Special Air Service Regiment (SASR). While the SASR uses weapons of essentially the same pattern built by Colt for export (Colt uses different models to separate weapons for the U.S. military and those for commercial/export purposes), the British SAS uses a variant on the basic theme, the Colt Canada (formerly Diemaco) C8SFW. The M4 carbine is slated to eventually replace the M16 rifle in the United States Army. M4 MWS (Modular Weapons System) Colt Model 925 carbines were tested fitted with the Knight's Armament Corporation (KAC) M4 RAS under the designation M4E2, but this designation appears to have been scrapped in favor of mounting this system to existing carbines without changing the designation. The U.S. Army Field Manual specifies for the Army that adding the Rail Adapter System (RAS) turns the weapon into the M4 MWS or Modular Weapon System. M4A1 The M4A1 carbine is a fully automatic variant of the basic M4 carbine intended for special operations use. The M4A1 has a "S-1-F" (safe/semi-automatic/fully automatic) trigger group, while the M4 has a "S-1-3" (safe/semi-automatic/3-round burst) trigger group. The M4A1 is used by almost all U.S special operation units. The M4A1 is especially favored by counter-terrorist and special forces units for close quarters combat because of the carbine's compactness and firepower. These features are also very useful in urban warfare. It is effective at ranges of 150 meters (160 yd) or less and has a maximum effective range of about 500 to 600 meters (550–660 yd). left|thumb|200px|Another shot of some M4A1s.(Notice that the sights make it look cooler) All U.S. Army forces will begin replacing their basic M4 carbines and all 600,000 M16 rifles with the M4A1 variant in 2014. The M4A1 in turn would likely be replaced with the Individual Carbine. Replacement of the M16 would come from the Individual Carbine instead of the M4A1 if procurement was attained. In the last few years, M4A1 carbines have been refit or received straight from factory with barrels with a thicker profile under the handguard. This is for a variety of reasons such as heat dissipation, which is useful due to the complaints of high-heat production from test soldiers, which occurs during full-auto and accuracy as a byproduct of barrel weight. These heavier barrel weapons are also fitted with a heavier buffer known as the H2. Out of three sliding weights inside the buffer, the H2 possesses two tungsten weights and one steel weight, versus the standard H buffer, which uses one tungsten weight and two steel weights. These weapons, known by Colt as the Model 921HB (for Heavy Barrel), have also been designated M4A1, and as far as the government is concerned the M4A1 represents both the 921 and 921HB. Mark 18 CQBR Current contractor for the Mark 18 is Colt & Lewis Machine & Tool NSN 1005-01-527-2288. It is equipped with a 10.3" barrel. Users * Afghanistan: Used only by Afghan Army commandos.[[|25]][[|26]] M4s sold as part of a 2006 Foreign Military Sales package.[[|27]] Additional M4s sold as a 2008 Foreign Military Sales package.[[|28]] * Australia: Used by the Special Operations Command,[[|29]] Clearance Divers.[[|30]] and Police Tactical Groups[[|31]] * Bangladesh: Used by Bangladesh Paracommandos, Dhaka Metropolitan Police SWAT teams and Special Warfare Diving And Salvage[[|32]] * Bahrain: M4A1s sold as a 2008 Foreign Military Sales package.[[|28]] * Belize: M4s/M4A1s sold as part of a 2006 Foreign Military Sales package.[[|27]] * Brazil: Used by Military Police of Rio de Janeiro State.[[|33]] * Canada: C8 rifle.[[|34]] * Czech Republic: The M4 Karabin A3 is used in small numbers by specialized units of the Czech Army.[[|35]] Known to be in use by the 601st Special Forces Group in 2006 to replace the Sa vz.58.[[|36]] * Colombia: M4A1s as part of a 2008 Foreign Military Sales.[[|28]] * Ecuador: M4s sold as a 2008 Foreign Military Sales package.[[|28]] * El Salvador: M4s sold as part of a 2007 Foreign Military Sales package.[[|37]] Additional M4s sold as a 2008 Foreign Military Sales package.[[|28]] * Georgia: Georgian Armed Forces.[[|38]][[|39]] * Greece: Used by EKAM.[[|40]] * Hong Kong: M4A1 by Special Duties Unit of the Hong Kong Police Force[[|41]] * Hungary: M4A1 SOPMOD by Hungarian Special Force [[|42]] * India: M4A1s as part of a 2008 Foreign Military Sales.[[|28]] M4A1 is also used by the Mizoram Armed Police, and Force One of the Mumbai Police.[[|43]][[|44]] * Indonesia: Used by Detachment 88 Counter-terrorism Police Squad operators.[[|45]] Also used by Komando Pasukan Katak (Kopaska) tactical diver group and Komando Pasukan Khusus (Kopassus) special forces group.[[|46]] * Iraq: Used by the Iraqi Army.[[|47]] Main weapon of the Iraqi National Counter-Terrorism Force.[[|48]] * Israel: Sold as part of a January 2001 Foreign Military Sales package to Israel.[[|49]] * Italy: Only Special Forces[[|50]] * Jamaica: M4s sold as part of a 2007 Foreign Military Sales package.[[|37]] * Japan: M4A1s as part of a 2008 Foreign Military Sales package.[[|28]] M4A1 SOPMOD rifles are in use by the Japanese Special Forces Group.[[|51]] * Jordan: M4s sold as part of a 2007 Foreign Military Sales package.[[|37]] Additionals M4s sold as a 2008 Foreign Military Sales package.[[|28]] * Kosovo: Kosovo Security Force[[|52]] * Lebanon: M4 components being sold to Lebanese special forces.[[|53]] M4/M4A1s sold as a 2008 Foreign Military Sales package.[[|28]] * Macedonia: M4s sold as a 2008 Foreign Military Sales package.[[|28]] * Malaysia: Made under license by SME Ordnance Sdn Bhd.[[|54]] To be used by the Malaysian Armed Forces, special forces of Malaysian Maritime Enforcement Agency and Royal Malaysian Police.[[|55]] * Nepal: Sold as part of a 2005 Foreign Military Sales package.[[|56]] * New Zealand: Used by NZSAS operators and the police Armed Offenders Squad.[[|57]][[|58]] * Panama: M4A1s sold as a 2008 Foreign Military Sales package.[[|28]] * Philippines: M4/M4A1s sold as a 2008 Foreign Military Sales package.[[|28]] Two variants of the M4 carbine are made by Floro International Corporation, consisting of the M4A1 5.56MM RIFLE and the M4A1 Model-C 5.56MM RIFLE.[[|59]][[|60]] * Poland: Used by Polish special forces unit Grupa Reagowania Operacyjno-Manewrowego (GROM).[[|61]] * Portugal: Used by Marines special forces DAE (Destacamento de Acções Especiais).[[|62]] * Serbia: Used by various police units.[[|63]] * Singapore: Used by the Singapore Armed Forces Commando Formation.[[|64]] * Taiwan: Used by National Police Agency (Republic of China) [[|65]] * Thailand: M4A1s sold as part of a 2006 Foreign Military Sales package.[[|27]] * Tonga: M4/M4A1s sold as a 2008 Foreign Military Sales package.[[|28]] * Turkey[[|66]] * United Arab Emirates: Purchased 2,500 M4 carbines in 1993.[[|67]] * United States[[|34]] * Yemen: M4s sold as part of a 2006 Foreign Military Sales package.[[|27]]